Spectrometers, spectrophotometers, and related spectrographic instruments are generally used to analyze materials in view of the absorption and reflection of waves of various wavelengths. For example, a spectrophotometer may measure materials in view of the absorption and reflection of visible, ultraviolet, and near-infrared light waves. The main components of a spectrophotometer include a wave source, a chamber or suitable means for holding a sample under test, and a wave radiation detector.
Generally, a spectrophotometer operates by directing radiation at a wavelength (or range of wavelengths) toward a sample under test, detecting an amount of radiation absorbed by the sample at the specific wavelength, converting the amount of absorbed radiation into a number or other metric, and displaying the number or metric for the specific wavelength. This process may be repeated over different wavelengths of radiation until a full spectrum of radiation has been analyzed for the sample under test.
Spectrographic instruments may be used to determine certain characteristics of materials under analysis. In that context, concentrations of constituents or physical characteristics of materials may be measured. For example, spectrographic instruments may be used to determine oil, protein, and moisture content in grain, fat content in meat, and the various contents in milk. Spectrographic instruments may also be used to analyze samples of bodily fluids, pharmaceuticals, and synthetic materials, for example.
Typically, when different spectrographic instruments measure a same sample, each will provide an instrument-specific measurement result. That is, the measurement results will likely vary, at least partially, for each of the different spectrographic instruments. These differences in measurements may be attributable to variations in mechanical and optical tolerances, ages of the instruments, variations in repairs made to instruments, and/or fluctuations in operating environments of the instruments.